Traffic channelizing devices are used to warn and alert motorists of hazardous conditions existing on or about roadways and to direct or channel them along a designated course which may differ from the ordinary traffic route, for example, to direct traffic around construction areas.
Channelizers exist in a great many configurations and are made from a number of materials. For example, early on, fifty gallon steel drums were used as channeling devices, as are the orange, rubber cones with which most are familiar. Steel drums have largely been replaced by plastic barrels; plastic barrels are now commonly used in -situations where traffic channelization is intended for a sustained period of time or where high visibility is required. These plastic barrels are of a size and appearance suggestive of the steel drums and appear sufficiently formidable to warn motorists of hazards.
In order to impart added stability to plastic barrels, they are often filled with ballast, typically sand. In use, and particularly when ballasted, plastic barrels have proven to be effective, stationary devices capable of withstanding movement caused by wind and environmental variables or the irregular turbulence created by large, fast moving motor vehicles.
Despite the advantages of ballasted plastic barrels, there are disadvantages which derive from the use of ballast, particularly sand, as stabilizing material for traffic channelizers. Because it is inexpensive, readily available and relatively soft, sand is often selected for ballast. However, when the sand is spilled onto the roadway, for example, as the result of impact, it can reduce road contact of vehicle tires and create a condition which greatly impairs the motorist's ability to maintain control over the vehicle; both braking and steering can be affected.
An example of a ballasted plastic barrel is disclosed in U.S. Pat. No. 4,083,033. U.S. Pat. No. 4,083,033 discloses a two-piece plastic drum that can be assembled or detached and which has a plastic upper drum element and a plastic base in the shape of an open tray for receipt of a ballast. The device provides for the placement of loose or bagged sand placed in the open tray of the base to stabilize the combined barrel and base.
Certain significant problems are inherent to the two-piece device (actually a three-piece device given the requirement of a separate ballast) when in use, as noted above. Specifically, in ballasting with sand, the sand is most commonly placed in bags or stored in a soft breakable container which will dispense the sand, for example when run over by a motor vehicle tire or ripped by the vehicle undercarriage. Accordingly, sand is often spread across the roadway when there is a collision with a ballasted plastic barrel. This is undesirable from a safety perspective in that sand on dry pavement is known to reduce the friction coefficient between pavement and the surface of a tire, thereby increasing braking distances and making steering difficult. From an additional practical standpoint, the displacement of sand out of the ballast tray of the base creates more work and expense in that, prior to subsequent use, the sand ballast must be replaced and the dispersed sand removed from the roadway.
An additional disadvantage relating to some prior devices is that the base is typically made from a flexible, thermoformed plastic. After several impacts, and particularly when the base is either run over by a vehicle tire or entangled with the vehicle undercarriage, the base is damaged to the point that it can't be reused. Accordingly, the base element fails to provide important safety and durability considerations. In addition, the sand ballast has a significant height, creating an obstacle for vehicle tires, if struck directly.
In U.S. Pat. No. 5,026,204 the configuration of the base element is modified to provide for a molded, hollow chamber, which is filled through an opening, and then sealed. The vertical, height of this base is four inches. The base requires the inconvenient step of adding sand to the base--a function which invites human error. Moreover, by its nature, the thermoformed material comprising the base is vulnerable to the extremes and adverse affects of environmental factors, which factors invariably, threaten the structural integrity of the base, leading ultimately, to rupture of the base and dispersal of sand onto the surrounding pavement.
U.S. Pat. No. 5,201,599 also discloses a ballasted base. Like U.S. Pat. 5,026,204, this disclosure involves a molded, hollow chamber with an opening and a cover for receipt of a ballast and for use in conjunction with a first, barrel-like element. As distinguished from the preceding invention, however, the invention of this patent requires the placement of a solid ballast means within the dome-shaped, molded chamber. The disadvantages associated with this device are similar to those described above with respect to convenience, the possibility that the ballast will not be securely added to the base in order to avoid leakage, and the short life expectancy of the base due to the material of which it is constructed and the stress imposed upon that material by extreme environmental factors as well as that caused by the repeated insertion and removal of ballasting means.
More recently, a base for traffic barrels has been produced from recycled rubber. This base is described in U.S. Pat. application Ser. No. 08/344,355, filed Nov. 23, 1994, now U.S. Pat. No. 5,451,118. The recycled rubber base does not require a separate ballast and has a low profile which reduces the barrier effect of the base itself.
The present invention also overcomes the disadvantages described for ballasted bases and produces a truly two-piece channelizing device. The base element does not require the addition of a separate ballasting material. Accordingly, the present invention avoids the described problems associated with sand ballasted bases, including fillable bases, by providing a durable, high-density, ultra low-profile and unitarily solid base element made from an inexpensive material, such as recycled rubber. The base of this invention is an improved base of the self-ballasting type described in U.S. Pat. No. 5,451,118.
Disposal of solid waste, including used motor vehicle tires, is a major environmental problem. Landfill approval and environmental standards grow increasingly strict; fewer acceptable means of disposal remain. The present invention contributes to solution of the tire disposal problem by providing an additional commercial use for recycled tires. The instant invention, presents an environmentally prudent and responsible alternative to the landfilling of used motor vehicle tires. The rapid acceptance of the high density bases, by the highway safety industry, indicates that this product has positively contributed to recycling efforts for used tires.
The properties of rubber include exceptional durability, high density and a natural elastic character. These properties enable recycled rubber material to produce a base element which unexpectedly eliminates many of the hereto required labor steps and associated adverse safety implications of post-manufacture ballasting, while providing a device of exceptionally low profile suitable for being repeatedly impacted by motor vehicles without threat to its structural integrity, and thus, its expected useful life. The exceptionally low effective profile mitigates against loss of control of a motor vehicle, as can occur due to tire contact with a thick conventional base and ballast.
Moreover, the structure of the improved base permits a maximum ballasting effect without using excessive weight in the base, greatly increasing the convenience of use and economy of the base itself. A typical base of this type weighs between about eighteen to twenty pounds. This improvement is achieved by strategically placing the substantial portion of the mass of the base at the horizontal extremity or periphery of the base. The mass is also placed as low as possible, consistent with the functioning of the base. The center of the base is free of material, or substantially so. As a result, a strong self-righting moment is achieved by the base without the need for excessive mass. The weight of the base is thus substantially reduced. This also results in a cost of material savings as well as savings in shipping cost. Further, there is an added convenience in that the bases are easier to carry and use on the job. The lighter weight may also reduce the risk of worker injury. As a result, there may be a reduction of lost worker time, fewer insurance claims and a reduction in related costs.